1. Field of the Invention
The present invention relates to a method and apparatus for controlling power of a Base Station (BS) in a wireless communication system. More particularly, the present invention relates to a method and apparatus for controlling power consumption of the BS in the wireless communication system.
2. Description of the Related Art
In a wireless communication system, a Base Station (BS) consumes a lot of power when performing traffic transmission and reception in order to provide a stable communication service to a large number of subscriber terminals within its service area. Along with the growth of large-capacity data services, such as a multimedia service, the power consumption of the BS has been correspondingly increasing. Therefore, research is being conducted on techniques to reduce the power consumption of the BS.
For the most part, the power consumption of the BS is attributed to an amplifier that amplifies signals. While there are notable achievements in the research on increasing the amplification efficiency of the amplifier, there is a need for research on power control of the BS according to the variations of transmitted and received traffic. In fact, the traffic requirements of users for the BS fluctuate between the day and the night on a daily basis.
FIG. 1 is a graph illustrating traffic load variations over time at a BS according to the related art.
Referring to FIG. 1, reference numeral 101 denotes a curve illustrating a traffic load corresponding to the traffic requirements of users that rapidly increases during the day and rapidly decreases at night.
However, the amplifier of the BS constantly amplifies received signals and thus consumes a similar amount of power irrespective of the higher traffic loads during the day or the lower traffic loads during the night. In this case, electrical stress and thermal stress imposed on the hardware of the BS decreases the lifetime of components of the BS. As a result, the Mean Time Between Failure (MTBF) of the BS is reduced.
Recently, a technique for reducing the average power consumption of the BS by directly manipulating the power supply of the amplifier according to traffic-changing time zones by a BS operator has been proposed.
FIG. 2 is a graph illustrating power consumption over time at the BS according to the related art.
Referring to FIG. 2, reference numeral 201 denotes a curve illustrating normal power consumption when the BS operator supplies a maximum amount of power to the amplifier during the day, which is when a lot of power is needed, and a reduced amount of power to the amplifier in time zones in which less power is needed. However, the power control technique based on the BS operator's manipulation does not allow for a fast enough response to a change in traffic and thus the usefulness of its implementation is limited.
While power consumption of the BS amplifier has been described above, it is also desirable to efficiently reduce the power consumption of other components such as a channel card and a main processor in the BS.